The thread that runs from the brutal police killing of George Floyd through to the toppling of Edward Colston’s statute in Bristol to the renewed calls for Cecil Rhodes to fall – the thread, that is, from Minneapolis, through Bristol, to Oxford - is a straight one. But although the events in Oxford can be understood through the prism of events over the past few weeks, they have much deeper roots, and those roots lie not only in the tortured history of race relations in the US or the slaving history of the British Empire but in vast tectonic shifts in the size and movements of populations. Demography, as so often, is the missing element in the story.